Watt Traders (Japanese: ワットショップWatt Shop) are NPCs who sell items in exchange for Watts. Watt Traders can most prominently be found in the Wild Area, where they have the appearance of League staff and also offer other services, including organizing the Rotom Rally (Japanese: ロトムラリーRotom Rally).
The first TR any Watt Trader offers always is between TR00 and TR49 (inclusive), and increases each day (where TR49 becomes TR00), if the game was saved the day before. Within that domain, each Watt Trader's first TR is seven more than the last one's, in the order shown above; e.g., if the Watt Trader at Meetup Spot offers TR00, the one at East Lake Axewell offers TR07, etc.
Any Watt Trader's stock solely depends on the first TR he offers, in the following way:
The second TR is 24 more than the first
The third TR is 42 more than the first
The fourth TR is 67 more than the first (or, if that would result in 100 or more, 100 less than that)
The fifth TR is 96 more than the first (or, if that would result in 100 or more, 100 less than that)
Unlike Poké Marts, purchasing 10 or more Poké Balls at once from a Watt Trader does not award bonus Premier Balls.
The Rotom Rally is a competition that requires the player to ride the Rotom Bike and reach the location of another Watt Trader in within a predefined amount of time. The destination can be any Watt Trader the player has previously visited. Each possible route comes with a suggested time that varies with the distance between two locations, ranging from as low as 30 seconds (the Hammerlocke Hills to the Giant's Cap or vice versa) to as high as 190 seconds (the Hammerlocke Hills to the Dappled Grove or vice versa). However, the displayed time for a route does not match the effective time limit available to the player, which always begins at 30 seconds.
During the Rotom Rally, when the player passes through a white balloon, the Rotom Bike receives a temporary speed boost. When passing through a red balloon other than the one that marks the finish line, the player receives a 15-second time bonus and the next set of balloons will appear on the path ahead. Contacting wild Pokémon does not trigger a battle but instead causes the bike to spin to a stop, costing the player speed. Pressing A, X, +, -, ZL, or ZR at any time will pause the bike and the timer, and prompt the player if they want to withdraw from the race. The race will also end automatically in failure if the player runs out of time, or enters the Wild Area Station, Motostoke, or Hammerlocke.
After successfully completing the Rotom Rally, a box will pop up showing the endpoints and a score, so that a screenshot can distinguish all the possible routes. This score is calculated as , where P is 600 if the selected route uses one of the three northern endpoints (Bridge Field, Giant's Cap, or Hammerlocke Hills) along with one of the four southern endpoints (Meetup Spot, Dappled Grove, East Lake Axewell, or Giant's Seat), or else 500 if both endpoints are on the same side of the Motostoke River. The player will receive TM14 (Thunder Wave) for their first completed race, a Fast Ball for their eleventh completed race, and TM80 (Volt Switch) for the first time a race is completed with a score above 20,000 points (other than the first completed race overall). A sufficiently high score requires finishing the race with more than 33.33 seconds left for routes that involve crossing the river, or 40.00 seconds left for routes that don't.
At the end of any race, completed or otherwise, the player receives Watts: 3 W for every white balloon hit over the course of the race, 15 W for every red balloon hit, and if the race was completed, an extra 1 W for every 300 points of score.
Outfit color change
Watt Traders will offer to change the color of the Rotom Bike outfit free of charge. He will offer colors that match the type or types of the first Pokémon in the player's party, as well as Rotom colors.
Rotom Bike upgrade
Watt Traders will offer to improve the Rotom Bike by boosting its turbo-boost charge speed. They can improve the bike up to three times; they will charge 1,000W for the first upgrade, 3,000W for the second, and 5,000W for the third.
On the Isle of Armor, a Watt Trader is located in the Fields of Honor, right in front of the Master Dojo. This Watt Trader has the appearance of a dojo member, does not offer additional services, and has a fixed stock:
This section is incomplete. Please feel free to edit this section to add missing information and complete it. Reason: exact stock pattern today's highlight offers
In the Crown Tundra, a Watt Trader is located at Snowslide Slope, near the Giant's Bed border. His regular stock consists of three distinct Poké Ball variants, a Hyper Potion, a Wishing Piece, and a set of ten consecutive TRs (all offered at the same price as at Watt Traders at the Wild Area). In addition, this Watt Trader also offers "today's highlight", a special offer that changes daily, and can only be purchased once per day.